METAMERA: the segments into which the embryo breaks up.

METAMERISM: the segmentation of the embryo.

MONERA: the most primitive of the unicellular organisms.

MONISM: belief in the fundamental unity of all things.

MORPHOLOGY: the science of organic forms (generally equivalent to anatomy).

MYOTOMES: segments into which the muscles break up.

NEPHRA: the kidneys; hence:—
Nephridia: the rudimentary kidney-organs.
Nephrotomes: the segments of the developing kidneys.

ONTOGENY: the science of the development of the individual (generally equivalent to embryology).

PERIGENESIS: the genesis of the movements in the vital particles.

PHAGOCYTES: cells that absorb food (phagein = to eat).